Ion-exchange resins are widely used for the isolation and purification of commercially significant ionic species. Due to the difficulties of working with heterogeneous systems, methods of studying ions directly adsorbed on ion-exchange resin beads are limited. Carbon-13 nuclear magnetic resonance has the powerful capability of being able to identify molecular structures in amazing detail. A carbon-13 identification of a carbon-containing ion directly adsorbed on ion-exchange resins may in many cases be definitive.
Ion-exchange resins are used to adsorb uranium carbonate complexes in uranium extraction process streams used in the recovery of uranium. The recovery of uranium from uranium ores conventionally involves leaching the ores with an acid or basic solution. The formation of the soluble and extremely stable uranyl tricabonate anion, UO.sub.2 (CO.sub.3).sub.3.sup.4-, however, makes the use of alkali and ammonium carbonate salts particularly advantageous in the leaching process. In the standard procedure, the solution and/or slurry resulting from the leaching process is, in turn, contacted with a strong base anionic-exchange resin such as Dowex 21K (tradename for strong base anionic resin manufactured by Dow Chemical) on which the uranyl tricarbonate anion is directly adsorbed to thereby isolate the uranium. It would therefore be very much desired to be able to monitor the presence and concentration of the uranium complexes loaded on the anion-exchange resins for determining the nature of the process stream.